Rheostat.



H. J. WIEGAND.

RHBOSTAT.

APPLIGATION FILED MAR. 29, 1909. v

Patented Feb. 22, 1910.

v 2 SHEETSSHEET l.

UNITED wis PATENT HENRY J. wmcmmi, or MILWAUKEE, Wisconsin, ASSIGNOR 'ro THE common HAMMER mm. 00., or MILWAUKEE, WISCONSIN, A oorronn'rronor wrsconsm.

nnsosm'r.

To all who m it-may concern:

Be itknown thatI, HENRr J. \VmcAND, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and v i accom an *in drawin formin a art of this specification.

My invention relates to improvements in rheostats, and more particularly to resistance units and to the method of mounting the same.

One object of my invention is to so'form 'a resistance unit from a thin sheet of suitable resistance material as to obtain the requisite rigidity ofv the same, A further object of my invention isto mount the units so as to secure the best possible ventilation thereof. 1 1

A further object of my invention is to In order that my invention may be more thoroughly understood, I have illustratedone embodiment of the same in theaccompanying drawings.

In the accompanying drawings,Figure 1 is an elevation of a rheostat embodying my invention, a portion. of the front being broken away; Fig. 2 is a side elevation of the rheostat shown in Fig. 1 with the casing removed and parts of the device being shown in section; Fig. 3 is a plan View of one of the resistanceunits; Fig. 1 is a sectional view of the unit shown in Fig. 3, as seen on line 4- 1; Fig. 5 is a bottom plan view of one of the spacing terminals, and Fig. 6 is a central sectional view of a portion of one of the resistance units and its spacing terminal.

In the embodiment of my invention shown, I have provided a supporting frame consisting of'vertically arranged bars 1, and horizontally arranged bars 2, secured together by means of bolts 3.- lhebars 1 and 2 are preferably formed of angle iron, as by such construction a very light and rigid frame may be secured. A casing. 4 pro on ably formed of foraminous material, is secured tothe frame in any preferred manner,

Specification of Letters Patent. Patented Application filed Marcn29, 1809. Serial No. 486,514.

' means.

as by screws The sides of the casing arepreferably made shorter-than the frame so.

Feb. 22, 1910,

as tp leave openings at the lower ends thereof. H Where such a construction is used, bind-. ing strip 6 are preferably disposed over the lower en of the sides, as otherwise a ragged edge would be left. A pair of supporting 7 members 7', for the resistance units, are oppositely disposednear the upper-ends of the bars land secured thereto in anypreferred manner, as by means of bolts or screws 8. Oppositely disposed blocks 9 and 10, preferablof insulating material, having grooves 11 in one 'facethereof, are secured near the lower end of the frame for a purpose hereinafter set forth. When it is desired to suspend theframe from the ceiling, the bars 1 are extended and provided with means whereby the same may be fastened in place If it is desired to fasten the frame against a wall, the ends of two of the side bars are extended and provided with like fastening In the embodiment of my invention, shown in the drawings, I employ resistance units 12 which are formed of a thin sheet of suitable material. German-silver provides an efficient material for such units, but, of course, other materials may be used. Usually such a construction would be impractical, as the units would be so flimsy as to be liable to buckle when heated and cause short circuits in the rheostat. To obviate this dan' er I provide the units with suitable stren t ening beads or ribs. As illustrated, I ave provided a continuous bead 13, extending around the outer-edge of each unit. This bead strengthens the unit,,both. longitudinally and transversely. In addi-. tion to the bead 13, I, preferably provide curved beads 14, which also act to strengthen the units both longitudinally and transversely. It should be understood, however,

that the ribs or beads may be of any preferred formand located as desired. Terminails 15 are secured ,to each resistance unit at the ends thereof, by means of which the units may be mounted in a rheostat and else-- trieally connected in circuit. The resistance units are-provided at opposite ends with openings 16.. Surrounding the openings 16 are collars 17,- which may be struck upfrom the units, or formed in any other suitable washers, have an opening 18 therethrough. Each of the terminals is provided with an annular groove- 19 adapted to receive a collar 17 therein. the inner wall of the roove is thensprea outwardly by means of a suitable punch, so asto tightly-impinge the collar between the walls of the groove, thus securely fastening advantage.

the terminals in position. The terminals 15 are preferably formed with a groove 20 around the edge thereof, whereby a terminal of light weight, but with a large contact 7 surface, is secured;

disks 26 are interposed, between certain of the units so as to control the-path of the cur-' rent therethrough. The insulating washers may -be interposed between the units in any preferred manner to direct the flow of current therethrough. In Fig. 2, of the drawings, I have shown the units arranged in series, the path of the current from the terminal 27 being traced through the first'unit to the third unit, thence through the second unit to the fourth unit, and so on. However, it will be understood that the units may be connected in various other ways. When the units have been properly mounted upon the rods they are secured in place by nuts 28, and the rods 22 and 23 are secured in the supporting members 8 by means of nuts 29,

or in any desired manner, and are preferably insulated therefrom. The ends of the rod 21 are designed to extend into the grooves 11 in the blocks 9 and 10. The grooves will maintain the units in proper relation in the rheostat, but will allow the rod to move therein to compensate for any expansion-or contraction of the units during service.

While I have described the preferred form of my invention, I desire it to be understood that various modifications may be made therein without departing from the scope of my invention.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A rheostat, comprising a plurality of elongated resistance plates divided into groups disposed obliquely in opposite directions.

2. In a rheostat, in combination, a plu;

The material formin supporting rahty' of elongated resistance elements, a

members, each connected to the opposite end of a plurality of said elements.

3. In a rheostat, in combination, a pairof rods arranged substantially parallel and in substantially the same plane, and another rod arranged substantially midway between said first-mentioned'rods and ina diflerent plane therefrom, and a plurality of elongated resistance plates, each having one end secured to the last-mentioned rod and its opposite end connected to one of the other of said rods.

4:. In a rheostat, in combination, a pair of supporting rods arranged substantially parallel in'the same horizontal plane, an additional supporting rod arranged below and substantially equldistant from said firstmentioned rods, and a plurality of resistance units formed from a thin sheet of material and each having a pair of terminals, one

terminal of each unit being arranged on the lower rod, and the other terminals of said units being arranged on one of said pair of rods.

5. In a rheostat, incombination, a frame, a plurality of resistance units, each formed from a thin sheet of material, said units being arranged in groups disposed obliquely in opposite directions.

(3. In a rheostat, in combination, a frame, a plurality of resistance. units, each formed from a thin sheet of material and having 'astrengthening bead formed thereon, said units being arranged in groups, disposed obliquely in opposite directions.

7 In a rheostat, in combination, a frame, a plurality of resistance units, a single supporting member for the lower end of all of said units, a pair of supportingmembers for the upper ends of said units, the adj'oiuing units being alternately supported by said pair of supporting members, the two groups of resistance unitsbeing disposed obliquely in opposite directions.

8. In a rheostat, in combination, a frame having a pair of guiding blocks arranged near the lower portion thereof, a plurality of reslstance units each formed from a thin sheet of material and having terminals at opposite ends thereof, a rod extending through the lower terminals of all of said units, a pair of rods, each passing through the upper terminals of a portion of said units, said pair of rods being supported by said frame, and the other rod having its ends disposed in the guiding blocks.

9. A resistance unit formed from a thin sheet of material, said sheet of material having an. endless strengthening bead struck having longitudinal and transverse strength, ening beads struck from the surface thereof.

having strengthening beads struck from the transverselyextending strengthening beads. 12, A resistance unit formed from a thin sheet of material, said sheet of material 13. A resistance unit, formed from a'thin sheet of material, having fa continuous strengthening bead formed around-the. edge thereof, andalso transversely. extending strengthening beads.'

14. A. resistance unit, formed from a thin sheet'of material, having a struckup por- .tion and a terminal adapted to be clamped to the struck-up portion thereof:

15. A resistance unit, formed from a thin sheet of material, said resistance'unit having an aperture therein, and a collar around said-aperture, a terminal for said unit having a groove therein for receiving said col lar, said terminal being adapted to v be clamped onto said collar.

16. A resistance unit, formed from a thin sheet of material, said resistance unit having apertures in its ends and collars around said apertures, terminals for said unit, eachterininal having a groove therein adapted to receive one of said collars, the Walls of said groove being impinged againstthe col lars. v a

17. A resistance unit, formed from a thin sheet of material, having apertures therein and collars formed around said apertures, terminals having an aperture therethrough and having a groove formed around said aperture. forreceiving a collarthereiii, the aperture in each terminal being expanded \vlierebyvthe Walls of the groove will impinge said collarrtherebetween.

18.. A resistance unit, formed from a thin sheet of material, a strengthening bead formed around the edge thereof, and strengthening bea'ds formed transversely thereof, said unit having an aperture at each end and'collars formed around said aperture, a'te rminal for each end' of said unit,

said terminals having a groove for receiv- *inga collar therein, thefwalls of said groove being forced together 'torimpinge the collar th'erebetween. 4

19. In a rheostat, in combination, a supporting frame, a plurality of resistance un ts, means for rigidly securing one end oi all of saidunits in said frame, and means for loosely S pporting the Opposite ends of i said units in said frame. 20. In-a rheostat, in combination, a supporting frame, .a plurality of elongated resistance units havin terminals at opposite ends thereof, means for rigidly securing one terminal of all of said units in said frame, and means for loosely supporting the opposite terminals of said units in said frame. In Witness whereof, I have hereunto subscribed my name in the presence of two witnesses. I v a HENRY J. \VIEGAND.

Witnessesf S. W. Fm GERALD 'F. H. HUBBARD. 

